Islamic law is divided into the Shari`ah and and the Fiqh. The first is the sacred law and the second deals with jurisprudence. Not being muslim I know little about these and am not fit to pass comment. They seem to be rooted in tradition and attempt to give adive on how to behave in a just and religious way. As with all systems of law an extreme stance can lead to repressive behaviour. The Taleban seem to practice this law literally